The short promotional teaser of Sonic Advance was presented on E3 in 2001, where it was announced that a Sonic game was under development for the Nintendo platform. The teaser showcased a short clip of Sonic running through an early version of the Neo Green Hill Zone.
Early screenshots featured on many different websites and in various magazines share a common element: the early HUD in the upper left corner of the screen showcases a different Ring icon compared to the one in the final game. Following image gallery shows these different HUD sprites without any notable differences:
The screenshot on the right presents a different-looking Special Stage, with the tubular tunnel having basic tiles as opposed to the detailed ones used in the final game. All the sprites for the Rings and Bombs are also completely different.